I have a 1999 F-150 with a battery light that comes on when the truck is at idle or low rpms. As I accelerate it goes off. Is this an alternator going bad or do I have a battery problem. I have checked the wires best as I can all seems fine. Any ideas?

 

At idle how many volts are you running??

Good sign of a alternator going out...

 

I don't have a meter but the guage on the dash reads normal and most of the info I 've read shows the light coming on as rpms increase mine goes off. Guess I'll take it tomorrow to get tested, just afraid to drive it much and I still have to drive it to work.

 

Take it to a parts store for an alternator and battery load test. They can do it in the vehicle in the parking lot.